What began two years ago as an elaborate $18 million clubhouse reconstruction at Belmont Country Club has grown into a nearly $30 million fiasco, and now the club’s affluent, well-mannered membership has lost its collective cool.

Wealthy weekend golfers are standing up in meetings and demanding resignations. Millionaires are trading nasty e-mails­ — delineating their grievances and accusations with Roman numerals.

Backslapping has been replaced by back stabbing, and successful business people are doing “things that we would never do in our professional lives,” according to one message from the clubhouse building committee.

“Welcome to Belmonts very own - ‘Big Apple Circus’!!!,” Robert A. Schlager, president of Bulfinch Cos., wrote in an e-mail­ to club leaders last year.

Schlager had been asked by a friend on the building committee to offer advice on utility work and concluded that the club had a “team of misfits” handling the project.

A couple of members have dubbed the saga playing out in Belmont a worthy sequel to the drama of a similarly contentious clubhouse replacement at the Wellesley Country Club less than a decade ago.

As dysfunction reigns, the price tag on the clubhouse continues to grow, despite attempts to scale back building plans.

Members, who are charged as much as $65,000 to join the club — and pay about $22,000 per year in fees — have conceded that three pools won’t be necessary and now agree two will do. They have settled for merely doubling the size of their fitness center, rather than tripling it, as originally planned.

Amid the finger-pointing, a few facts are not in dispute. The most recent budget request for a 44,000-square-foot clubhouse, plus an 1,800-square-foot cabana, is $28.8 million.

Even discounting expenses that were not part of the original estimate, the project is roughly $8 million over budget, though the clubhouse design has shrunk by more than 10,000 square feet.

A projection by the club’s board of governors, contained in one of 18 e-mails obtained by the Globe, suggests the overruns will cost each member at least $28,000.

The club is on its third builder since Belmont’s zoning board approved the project in the fall of 2011. In one case, the club fired the builder. In another, the builder fired the club.

The current contractor, John Moriarty & Associates, hopes to finish construction next month, missing a January target by five months.

Beyond those basics, almost everything else is the subject of heated debate — especially the question of whom to blame.

Most of the nearly three dozen members contacted by the Globe requested anonymity or declined to comment on the project because club president Peter Kotzen asked all members not to speak to the press.

But conversations with six members and a review of internal e-mails suggest that much of the acrimony stems from clashes between building committee cochairman Jonathan Seelig and other club leaders, most notably former president Larry Uchill.

In one e-mail, Uchill accused Seelig of failing to stay on budget, making important decisions unilaterally, and ignoring qualified advice.

Another club member who has been involved in the project echoed Uchill’s description of Seelig’s performance, saying he has stubbornly driven the club from one mistake to the next while trampling critical voices.

Uchill, a partner at Boston law firm DLA Piper, declined to be interviewed for this story.

Seelig, a cofounder of Akamai Technologies Inc. in Cambridge, offers a very different version of events.

Seelig admitted that he and his committee made mistakes but denied being too controlling. Some errors might have been avoidable, he said, “but there also have been things that no one could have anticipated,” such as insufficient water pressure, which required the installation of a new system.

In addition, Seelig said, Belmont Country Club has incurred extra costs by putting its employees before the bottom line. Last summer, when there was no clubhouse to operate, the club paid its staff full wages, he said.

Discussing the string of broken budgets, Seelig did not blame anyone in particular. But in e-mails exchanged by club ­officials, Seelig and colleagues on the building committee complained at length about meddling by Uchill.

Last spring, with the club already working with its second builder, Suffolk Construction, Uchill and the board of governors decided to consider a lower quote from Moriarty. In a scathing e-mail to Uchill and members of the board, Seelig and four others on the building committee condemned what they called a “back channel price check on our project,” claiming the move had undermined their efforts.

Seelig and his colleagues said they had warned that the involvement of Moriarty would offend Suffolk chief executive John Fish — whose proposal had satisfied the building committee — and they were right. Fish walked away.

Uchill apologized in an e-mail­ to Fish for his role in the fallout and offered to resign as president, if Suffolk would continue as the clubhouse contractor.

Fish offered a terse reply: “No thank you!” He declined to be interviewed.

Blaming Uchill for the Suffolk debacle, Seelig and the building committee demanded “full autonomy” going forward, and the board of governors took their side.

First, the board asked Uchill to withdraw from day-to-day oversight of the clubhouse project. Five weeks later, the governors asked him to resign.

One longtime club member lamented the internal feud and said he believes all parties have acted in good faith.

“The overruns are unfortunate, but most of us can afford the cost,” said the member.

“It’s going to be fabulous, we’re all going to enjoy it, and people will forget about the fighting.”

In an e-mail to members last month, the board of governors acknowledged that the latest budget increase of $2.6 million is “very upsetting news” but said “this is not the time to point fingers or to create scapegoats.”

The board’s appeal for calm has not been heeded.

Club member Richard Grubman, a retired cofounder of the Boston hedge fund firm Highfields Capital Management, blasted the governors’ pacifism in a response e-mailed to the entire membership.

“Are you suggesting we just let it slide with no accountability as the membership picks up yet another bill for the mistakes of others?” wrote Grubman.

“It has become an ever increasing point of embarrassment and ridicule to be associated with this project . . . not to mention costly beyond any reasonable expectations, regardless of one’s means.”